Clark’s disguise is a lot more plausible if you consider that most people in Metropolis don’t think or believe Superman even has a secret identity to begin with. To them he’s just Superman 24/7.
Every time they read about him or hear about him he’s always off somewhere far away saving someone.
Why would they believe someone with all that power would be sitting right next to them?
It’s too ridiculous to be true.
It’s also similar to actors going out in public. A lot of them are able to fly under the radar simply because no one expects to see a well known celebrity slumming it with the rest of us. Bradly Cooper was on the New York subway and all he wore was a sweatshirt, sunglasses and a backwards cap.
No one realized it was him until much later. Michelle Obama went to Wal-Mart only a few weeks after the election when her face had been plastered everywhere. Once again her disguise was minimal. Just sunglasses and cap. Only the cashier recognized her when they asked for ID.
And finally think about Kenshin Himura
and Vash the Stampede.
When all their friends and allies first met them all they saw was an awkward and goofy dope who tripped over their own feet. And they all thought the same thing:
“No way this idiot could be Hitokiri Battousai/The Legendary Humanoid Typhoon.“
Clark’s glasses are only part of the act. His mild-mannered demeanor, some clumsiness, and a larger than life alter-ego do the rest.
Cheloneuniverse 